bts: Use public getter instead of class member

Change-Id: Ia7b37a4c721d7d02c516d8d3a5417d166f1d3bec
diff --git a/src/bts.cpp b/src/bts.cpp
index 62870db..8ccbee9 100644
--- a/src/bts.cpp
+++ b/src/bts.cpp
@@ -989,7 +989,7 @@
 
 	/* Make sure PDCH time-slot is enabled */
 	pdch = &bts->trx[rip->trx_nr].pdch[rip->ts_nr];
-	if (!pdch->m_is_enabled) {
+	if (!pdch->is_enabled()) {
 		LOGP(DRLCMAC, LOGL_NOTICE, "(TRX=%u TS=%u RFN=%u) Rx RACH.ind (PTCCH/U) "
 		     "for inactive PDCH\n", rip->trx_nr, rip->ts_nr, rip->rfn);
 		return -EAGAIN;